(a) Field of the Invention
The present invention relates to a traffic accident data recorder mounted on a vehicle for land transportation such as a car. The invention further relates to a traffic accident reproduction system for reproducing and reconstructing the traffic accident by using the traffic accident data stored in the traffic accident data recorder. Hereinafter this traffic accident data recorder will be called an ADVANCED VIDEO BOX (AVB).
(b) Description of the Prior Art
Most commercial aircraft and some private aircraft are equipped with an event recording device commonly called a "black box". This device recorded pertinent data from the major subsystems of the aircraft as the aircraft was operating. If an accident occurred, the "black box" generally can be retrieved from the aircraft and the recorded information can be extracted to determine the status of subsystems of the aircraft just before the accident. Such information can then be used to reconstruct the events leading up to the accident, and can help determine the cause of the accident. Black box recording devices have proven invaluable in aircraft accident reconstruction. However, this type of technology is quite expensive, and its use has been limited to more expensive vehicles, e.g., aircraft. In addition, it is believed that all such devices operate using a cumbersome magnetic tape to record data. These devices also tend to be larger, heavier, and consume more power than would be acceptable for automotive use.
In the area of automobile accident reconstruction in the past, an accident investigating officer generally determined how an accident most probably occurred by measuring, among other things, the length of skid marks, the extent of vehicle and nearby property damage, and the condition of the road at the time of the accident. This method of reconstructing accidents was expensive and inaccurate at times.
Generally, it is very advantageous to know the condition or state of a vehicle when a traffic accident has occurred involving the vehicle, in order to determine the cause of the accident. It is also very advantageous to analyze data of, for example, acceleration, angular velocity, etc. of the vehicle at the accident occurrence time. Transitory events, e.g., accident scenes in particular, must be accurately and quickly recorded in situ prior to the removal of the affected vehicles for purposes of later reconstructing the relative position of various features and objects and their relationship to fixed positions at the site. This was usually accomplished manually. The data collected was then utilized to establish the final position of the vehicles and associated debris as well as to provide information from which reasonable inferences might be drawn concerning the events leading up to the accident.
Because, by their very nature, vehicular accidents almost always occur on or adjacent to roadways, the conventional methods of accurately recording the data necessary accurately to establish relative vehicle positions with respect to fixed adjacent objects (e.g., road signs, telephone poles and the like) utilizing a roll-a-tape, clipboard and pencil required that the accident scene not be disturbed for an extended period of time prior to clearing. During this laborious investigation process, other vehicular traffic is either slowed or totally obstructed which can itself lead to secondary incidents or accidents involving other vehicles or individuals assisting at the scene.
It is therefore vitally important that the accident investigating officer record, and then clear, an accident scene as rapidly as possible. Nevertheless, the data recorded must be accurate and verifiable for later use in reconstructing the incident and formal procedures must be followed such that the integrity of the data gathered might be ensured. Heretofore two methods of determining distances regarding an accident scene have been generally employed utilizing a mechanical distance measuring device, e.g., a roll-a-tape combined with the manual recordation of the distances on a clipboard.
The "baseline" (or "baseline/offset") method was one recordation technique in which an imaginary grid or coordinate system was established overlying the accident scene with a first axis which was fixed between two permanent objects or positions adjacent to the site (e.g., traffic signs, utility poles and the like) which were utilized as control points. The accident investigating officer must then manually measure a series of distances along the first axis to establish various positions (e.g. the abscissa), at which positions the accident investigating officer must then additionally walk off and make a like series of right angle measurements to vehicle tires, skid marks and the like to establish the coordinate along the second axis (e.g. the ordinate). The resulting "x,y" values can then be utilized to reconstruct the accident scene on a grid for subsequent investigation.
An alternative technique was the "triangulation" (or "range/triangulation") method. In practice, this technique required that a pair of fixed object or position control points also be selected and the distance between them established by manual measurement. The accident investigating officer then positioned himself or herself adjacent to the various points of interest (e.g., the left front tire of the first vehicle, the right front tire of the second vehicle, and the like) and then walked off and measured the distance to both of the control points for each point of interest. The resultant data was then utilized to calculate the "x,y" position of the various points with respect to the control points by knowledge of the lengths of the three sides of the triangle formed.
In practice, the baseline technique was the most time consuming to implement in the field but was the most expeditious to reconstruct back at the police station. The converse was true of the triangulation method. However, regardless of the technique employed, current roll-a-tape, clipboard and pencil techniques were time consuming as well as being subject to measurement errors when obstructions were in the path of the measurement to be made and recordation errors which might not be detected until after the accident had been cleared. Moreover, during the entire process, the normal traffic flow at the scene was disrupted and the accident investigating officer was exposed to the attendant dangers of making the measurements for an extended period of time.
Short-distance, or residual-distance, recording devices have been provided in motor vehicles and have been used for analyzing the last distance travelled before a stop, possibly a stop which was caused by a collision. A wide range of recording principles were already known for devices of this type, e.g., principles which enabled immediate examination of the recordings, as well as those in which speed values were generally written into an electronic storage, continuously in a determined clock cycle as data records, sometimes together with other data, the least current data records being erased.
Special accident recording devices were also known in which accident data were determined, preferably by means of acceleration sensors, and were stored for a relatively brief period, in a time-based manner, wherein additional information which concerned, for example, brake actuation, blinker operation and illumination, was compiled as an interpretation aid. Such a device permanently stored the accident data when the vehicle actually underwent accelerations beyond the range of possible accelerations which were brought about by the nature of the road and the driving dynamics, i.e., in the event of genuine impacts caused by traffic accidents. In this way, the processor capacity and storage space can be confined to authentic accident situations.
Recordings made by devices of the first group can provide a certain support for recording and interpreting accidents in that the speed curve, which preceded the stopping of the vehicle, was analyzed on the spot and status data, which had been compiled, e.g., "brake applied", "blinker on" and the like, can be taken into account regardless of whether or not the vehicle had undergone an impact resulting from an accident.
However, the actual reaction of the driver, the driving situations which resulted neither in a stopping of the vehicle nor in a collision, or hit-and-run situations, cannot be detected because these recordings were overwritten when the vehicle resumed driving. The same can also be said of the devices which exclusively recorded collisions. While these devices enabled an exact analysis of the events which preceded and which followed an accident, this analysis can only be undertaken by experts. Also, the cost of such devices generally exceeded the acceptable limits for monitoring devices, which were not required by law, especially since they were used relatively rarely or not at all for the entire operating life of a vehicle. On the other hand, the first group of devices can be used much more frequently, namely, for traffic checks.
Generally, when a vehicle encountered a traffic accident, it was quickly braked or, without quick braking, it crashed against or collided with something, or something collided with it from behind. Therefore, if the acceleration and angular velocity of the vehicle were to be recorded, it is possible to know with their rapid changes the time when the traffic accident occurred. It would be useful to take a picture at the moment of an accident, however, when a vehicle collision occurred, there was no practical way to take a picture at the instant an accident has occurred. An impact-actuated inertial switch was required to trigger a camera. Various devices employed spring-biased movable masses to open or close an electrical circuit or do mechanical work when the device was subjected to a sudden acceleration change. The typical impact sensor utilized a movable mass that was biased to a normal position by compressed springs or magnetic attraction. The movable mass was often shaped in the form of a spherical or metal ball and was constrained to move through a closed chamber against the restraining force of the biasing means upon receiving an inertial force from the proper direction. By such means a photographic image at the instant of impact was said to be provided.
Many patents have been issued which purported to provide a system and method for reconstructing an accident.
U.S. Pat. No. 5,435,184, patented Jul. 25, 1995, by Pineroli et al., provided a device for detecting running variables e.g., the lighting up of a warning lamp, the positioning of a roll bar, the activation of a belt tightener and/or of an air bag, etc. in a motor vehicle. The device included at least two acceleration sensors to detect the longitudinal and transverse acceleration of the motor vehicle, and an evaluation circuit with a resettable time measuring unit which determined acceleration values from the sensor signals over a given period of time. A signal divider was connected to the signal output of each acceleration sensor to divide the sensor signal into a low-frequency (LF) signal component and a high frequency (HF) component. An adder was connected to the LF outputs of the signal dividers for the vectorial addition of the LF components of both sensor signals corresponding to the longitudinal and transverse acceleration components. A storage unit was connected to the adder and the time measuring unit to store the calculated acceleration values over the measured time. A control unit was connected to the HF outputs of the signal dividers to control the time measuring unit. There was no disclosure of any means for reconstructing an accident.
U.S. Pat. No. 5,445,024, patented Aug. 29, 1995, by Riley, Jr. et al. disclosed an automotive motive recorder, which recorded and stored the information necessary for a determination of the pre-impact speeds and the impact speed of a motor vehicle which was involved in a collision. Following an accident, the unit may be removed and be connected to a personal computer as a reader. With entry of the proper access code, the data pointer outputted the stored information in the correct sequence for analysis.
U.S. Pat. No. 5,446,659, patented Aug. 29, 1997, by Yamawaki, provided a traffic accident data recorder and traffic accident reproduction system which included an acceleration sensor, an angular velocity sensor, if necessary, a memory, and a control section for controlling the recording in the memory. When the output datum from the acceleration sensor or the angular velocity sensor exceeded a predetermined value, the control section recognized that time as a traffic accident occurrence time, and stored the acceleration data and angular velocity data before and after in the memory. By analyzing the data with a traffic accident data reproduction system, it was possible to reproduce the state of the vehicle at the traffic accident occurrence time.
U.S. Pat. No. 5,477,141, patented Dec. 19, 1995, by Nather et al., provided a registration arrangement for motor vehicles with a measured value presentation, which was said to be suitable for evaluating accidents. A storage arrangement was provided in which speed measurements were simultaneously written into at least two parallel storage branches. A plurality of time-limited storage areas were defined in each storage branch. Each storage area had a storage portion which can be operated as a ring storage and a storage portion which was arranged subsequent to the latter, which can be operated as a linear storage. The speed values, which were written into the ring storage in a continuous manner during the course of normal driving, were permanently stored in one storage branch when one criterion occurred, and in the other storage branch when the criterion which was greater than a deceleration threshold value occurred. Subsequent speed values were written into the linear storage of the respective storage areas until the set time limit, after which a free storage area of the respective storage branch was switched to.
U.S. Pat. No. 5,581,464, patented Dec. 3, 1996, by Woll et al., an apparatus and method for recording operational events in an automotive radar system. The invention provided what was called an Event Recording Apparatus (ERA) that recorded selectable vehicle performance, operational status, and/or environment information, including information which would be useful for accident analysis and updated software for use by a system processor which was capable of reading data from the ERA. The ERA included a non-volatile solid-state memory card, a memory card adapter which was located in a vehicle, and a microprocessor, either as part of the memory card or embedded in a system within the vehicle, for controlling the storage of data within the memory card. The ERA was configured to store such vehicle information as the closing rate between the recording vehicle and targets located by the radar system of the vehicle, distance between the recording vehicle and targets, vehicle speed, and such vehicle operational status and environment information as braking pressure, vehicle acceleration or deceleration, rate of turning, steering angle, hazard levels determined from a radar system processor, target direction, cruise control status, vehicle engine RPM, brake temperature, brake line hydraulic pressure, windshield wiper status, fog light status, defroster status, and geographic positioning information.
U.S. Pat. No. 5,696,705, patented Dec. 9, 1997, by Zykar, provided a system and method for data entry and retroactive reconstruction of the relative position of features and objects. In particular, this was provided with respect to transitory occurrences, utilizing a signal transmitting and receiving distance determining device. The system and method disclosed had especial applicability to the on-scene recordation and subsequent ex post facto reconstruction of traffic accident scenes by law enforcement officers. It was said to be readily implemented in conjunction with a commercially-available, laser-based speed and distance determining device otherwise usable for vehicle speed traffic monitoring functions, utilizing either triangulation or baseline/offset mensuration techniques.
U.S. Pat. No. 5,671,451, patented Sep. 23, 1997, by Takahashi et al., provided a data recording unit for use with a camera for recording information data, obtained through a GPS receiver, on a photographing film. The data recording unit included a selector for selecting a geodetic system from plural geodetic systems. A data converter was provided for converting a position information data, obtained through the GPS receive, to converted position information data in the geodetic system which was selected by the selector. A printing LED was provided for recording the converted position information data on the photographic film together with images which were photographed by the camera.
U.S. Pat. No. 5,680,117, patented Oct. 21, 1997, by Arac et al., provided a collision judging system for a vehicle. Such system included a sensor for detecting a relative speed between a subject vehicle and an object, and a judging section for judging a possibility of collision of the subject vehicle with an object based on the relative speed. In the collision judging system when an output from the differentiating device exceeded a preset value, a signal which was indicative of a command to prohibit the judgment of the possibility of collision in the judging section was outputted from the prohibiting-signal outputting device, thereby avoiding the unnecessary judgment of the possibility of collision in the judging section.
More recently, automobiles in the U.S. have been equipped with hidden "black boxes", stripped-down versions of the flight-data recorders that sometimes reveal the causes of airline catastrophes as previously described. The latest version of the recorder, known as a sensing and diagnostic module (SDM), kept track of the last five seconds before an impact. It cataloged speed, the position of the gas pedal, when the brakes were finally applied and whether the driver was belted, all in an attempt to improve safety through research.